Shotshells



Sept. 6, 1966 D. N. ATKINS ET AL 3,270,669

SHOTSHELLS Filed March 12, 1965 ..EIH B INVENTORS George David TAYLOR Francis Humnet Garland McCAFFREY David Norman ATKINS AGENT United States Patent 3,270,669 SHOTSHELLS David Norman Atkins and Francis Hamnet Garland McCatfrey, Brownsburg, Quebec, and George David Taylor, Lachute, Quebec, Canada, assignors to Canadian Industries Limited, Montreal, Quebec,

Canada Filed Mar. 12, 1965, Ser. No. 439,369 Claims priority, application Canada, June 16, 1964,

6 Claims. (01. 102-42 This invention relates to shotgun cartridges and, more particularly, to shotgun cartridges of the type wherein there is a gas-tight seal between the propulsion gases and the shot charge.

Shotgun cartridges made with a metallic head and a tubular paper portion are well known. Such shotgun cartridges normally comprise in combination Within the tube and in sequence from the metallic head, a cap or initiating means, a powder charge, one or more cylindrical sections or discs of Wad material over the powder charge to provide a cushioning medium and a partial gas seal, a quantity of metallic shot and an optional over-shot wad or disc. The open tube end is closed or sealed by means of, for example, a paper disc or by a folded crimp applied to the tube end.

Workers in the ammunition art, conscious of the requirements of shooters for a shotgun cartridge or shotshell which combines durability as a container with improved range and reduced scattering of the shot load, and conscious of the Wish of many shooters to reload and use again the spent cartridge casing, have provided many advances in the construction of shotshells. For example, Edwards, in British Patent No. 389,211, proposed the use of a cylindrical cup or envelope adapted to be inserted in a shotshell to hold the shot. By this means, the envelope would move easily through the bore or the gun and carry the shot for some distance as a grouped mass and so provide for reduced shot scattering and an improved shot pattern. Roberts, in British Patent No. 394,037, proposed that both the head and the tubular case of shotshells be constructed of a mouldable thermoplastic material. Holmes, in Canadian Patent No. 507,005, proposed a shotshell provided with a substan tially self-sealing wad between the propellent charge and the shot, which wad was of the character of a flanged disc with the flanges directed towards the propellent charge. Such a flange disc might be formed of any suitable sheet material. Miller et al., in Canadian Patent No. 664,533, proposed that the self-sealing disc or wad of Holmes be employed in combination with a C-shaped band or collar of thermoplastic material used as a Wrap around the shot. Calhoun et al., in Canadian Patent No. 586,189, proposed that a thermoplastic wad of H- shaped cross section be interposed between the propellent powder and the shot charge. More recently, Covington et al., in US. Patent No. 3,103,170, have proposed that the tubular casing member be made from synthetic linear polymer tubing, the said tubing having been oriented biaxially.

The aforementioned shotshell modifications, and in particular those associated with gas sealing and shot enclosure components, while offering some improved shooting characteristics, have not been without limitations which have contributed to some manufacturing difliculties and use restrictions. Whereas, for example, the use of a shot enclosure or envelope is desired, it is necessary that a material of construction therefor, be selected and employed which is sufficiently resilient and light in weight that it will fall away from the shot after discharge from the gun and yet will be sufficiently strong that it will not be destroyed by the impinging shot while still within the gun barrel. Similarly, Where a self-sealing gas-retaining wad is employed the material thereof must satisfactorily seal against the escape of propelling gases and yet be sufficiently strong and heat resistant that it will not be destroyed upon ignition of the powder charge. In addition, where a self-sealing wad of thermoplastic material is employed, it has been found that an additional wad of conventional material such as, for example, felt, must be employed to provide the absorbing effect long recognized in the art as essential in shot charge propulsion in order that the thrust of the expellinggases be cushioned and so prevent shot deformation and excessive pressure buildup. It has also been found that the effectiveness of the variously proposed novel shotshell components may vary with the configuration of the components. Frequently the thermoplastic component most effective in improving shooting performance may also be the component most difficult to manufacture by, for example, injection moulding, and may also be diflicult to insert in accurate position in the shotshell tube during manufacture.

Having regard to the aforementioned limitations, it is an object of the present invention to provide a shotshell wad column the components of which provide improved shooting characteristics.

Another object of this invention is to provide a shotshell wad column which may be simply and economically manufactured and assembled.

Yet another object of this invention is to provide a shotshell gas sealing component which combines the function of superior gas sealing with an essential cushioning function.

These and other objects of the invention will become apparent from the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a sectional view of a shotshell showing the placement of the shot containing component and the gas sealing and cushioning component according to one embodiment of the invention;

FIG. 2 is a perspective view of the gas sealing and cushioning component of the shotshell of FIG. 1;

FIG. 3 is a perspective view of the shot containing component of the shotshell of FIG. 1;

FIG. 4 is a perspective view of a cushioning component according to another embodiment of the invention;

FIG. 5 is a perspective view of a shot containing and gas sealing component according to an alternative embodiment of the invention; and

FIG. 6 is a section view of a shotshell embodying the components shown in FIGS. 4 and 5.

Referring to FIGS. 1, 2 and 3, a laminated paper 01 plastic tube 1 is held in a cup shaped metallic head 2 by means of compressed base wad 3 and crimps 4. A primer cap 5 is mounted in the central aperture of metallic head 2 and base wad 3. A powder charge 6 is shown adjacent to primer cap 5. Cup-shaped gas sealing and cushioning component 7 is inserted into tube 1 with its base supported by powder charge 6. Component 7 comprises a cup-shaped cylinder of, for example, polyethylene, the closed end of which comprises a thick base section 8 and the side wall 9 of which is tapered to a thin sect-ion 10 at the open upper end of the cup. Cup-shaped shot containing component 11 of, for example, polyethylene comprising a thickened, tapered base section 12 and a thin side wall divided by slits 13 into leaf sections 14, is inserted into tubular section 1 so that its tapered base end 12 engages the inner side of wall 9 of cushioning and gas sealing component 7. Shot containing component 11 is filled with shot 15 and the end of tube 1 is closed by means of tubeend folds 16 Upon firing the shell of FIG. 1, the gases generated by the ignition of powder charge 6 propel gas sealing and cushioning component 7 forward. Because of the mass of the shot load in shot containing component 11 and the inertia produced thereby, component 11 is forced into the cup of component 7, pushing the outside of tapered wall 9 against the bore of tube 1. The propulsion gases propel components 7 and 11 forward thus opening tube folds 16 and allowing components 7 and 11 with shot load 15 to enter the barrel of the shotgun. Because of the outward expansion of wall 9 caused by the tight fit of component 11 in the cup of component 7, a firm sealing action is formed between component 7 and the barrel of the gun to prevent the by-passing and escape of the propulsion gases. Soon after components 7 and 11 with shot load 15 leave the muzzle of the shotgun barrel, air resistance causes the leaves 14 of component 11 to fold backward permitting the shot 15 to travel forward in a tightly grouped mass. Components 7 and 11 thereupon fall away from the shot mass.

The combination of an upward facing, open cup, gas sealing and cushioning component and a tapered base, thin walled, cup-shaped shot container provides an optimum in cushioning, gas sealing and shot retaining properties. Because of the inwardly tapered side wall 9 of component 7, the initial propulsion of the shot load is cushioned against an abrupt shock which would otherwise tend to distort the shot and scatter the shot pellets. Such a configuration eliminates the need to employ any additional, for example, felt, wad as an over-powder shock cushioning unit. Additionally, because of the resilient nature of the material of component 7, the side wall 9 is readily expanded against the bore of tube 1 by the action of component 11 and likewise against the bore of the firearm to provide a tight seal to prevent the escape of propelling gases. Shot-containing component 11 provides, as well, an effective means of preventing the distortion of shot pellets through contact with the bore of the gun barrel, eliminates the depositing of lead from the shot upon the bore of the gun barrel and provides improved target patterns by virtue of retaining the shot pellets in a tightly grouped formation upon leaving the muzzle of the firearm.

FIGS. 4, 5 and 6 show and alternative embodiment of the improved shotshell and components of the present invention. Referring to these figures there is shown an over-powder wad 17 comprising a series of circular discs 18, 19 and 20 of, for example, polyethylene, with spaces therebetween, the discs being attached together by means of integrally moulded resilient plastic connectors 21 and 22. Discs 18 and 20 are similarly tapered inwardly in a direction towards their centers and away from disc 19 so that wad 17 is longitudinally symmetrical and may be inserted in tube 23 with either disc 18 or disc 20 above the powder charge 24. A thin-wall shot-containing sleeve component 25', comprising a sleeve open at both ends, is inserted in tube 23 the base end of the sleeve abutting the tapered edge of disc 20. Shot-containing sleeve component 25 of, for example, polyethylene, comprises four leaf sections 26 similar to those shown in component 11 of FIG. 3 of the drawing. An opening 27 of diameter smaller than the inner diameter of sleeve 25 is integrally moulded within sleeve 25, which reduced diameter opening is created by means of shoulder 28.

Upon firing the shell of FIG. 6, the gases generated by the ignition of powder charge 24 propel over-powder wad 17 comprising connected discs 18, 19 and 20 forward. As wad 17 is propelled forward, tapered disc 20 advances into shot-containing sleeve 25 and engages shoulder 28 causing an outward expansion of sleeve 25 against the inner bore of tube 23. Because of the resilient nature of the material comprising the over-powder wad 17 and the configuration of disc joints 21 and 22, an effective cushioning means is provided to prevent undesirable shock resulting from the initiation of powder charge 24. The expanding gases, from ignited powder charge 24 propel components 17 and 25 forward, thus opening tube folds 29 and allowing components 17 and 25 with shot load 30 to enter the barrel of the shotgun. Because of the outward expansion of the walls of sleeve 25 at shoulder 28, a tight seal is formed between component 25 and the gun barrel to prevent the by-passing and escape of the propulsion gases. Soon after components 17 and 25 leave the muzzle of the gun barrel air resistance causes leaves 26 to fold backwards permitting the shot 30 to travel to the target in densely grouped mass. Components 17 and 25 thereupon fall away from the shot load.

As may be seen, the combination of an inexpensive resilient, over-powder, cushioning wad of, for example, polyethylene and an inexpensive expandable, thin-walled shot-containing sleeve affords effective shock-absorbing, gas sealing and shot retaining properties. Also, the components may be simply manufactured and assembled and provide clean shooting conditions, that is, there is no disintegration of the wad column into fine particles which may blow back upon the shooter. In addition, because of the low cost of the thermoplastic wad column components and the ease with which they may be assembled into a shotshell, the wad and shot enclosure of the invention may be used without ditficulty by the shooter who chooses to reload spent cartridges.

The following examples illustrate the improved shotshell components of this invent-ion but the latter is in no manner to be limited in scope to the embodiments described.

Example 1 12 gauge shotshells were hand-loaded in a conventional manner wherein a A; inch thick cardboard, over-powder wad followed by a inch thick felt wad were employed. 1 /2 ounces of shot was placed directly into the body of the shell and the tube end was crimped closed. A sample of 10 shells th-us loaded were fired from a test gun barrel and an average of 62.5% of the shot pellets were delivered into a 26% inch circle at 35 yards range. A second 10 round sample containing a similar 1 /2 ounce shot load but loaded as shown in FIG. 1 of the drawing, employing a separate shot enclosure and an upwardfacing cup-shaped wad, delivered an average of 76.7% of its pellet load into a similar 26% inch circle at 35 yards range fired from the same test gun barrel.

Example 2 A sample of 10 commercial grade 12 gauge shotgun shells loaded with 1% ounces of shot over a paper and felt wad column, when fired from a test gun barrel, delivered an average 63.6% of their pellets into a 26% inch circle at a range of 35 yards. A sample of 10 similar shells provided with the shot enclosures and upward facing cup-shaped wads as shown in FIG. 1 of the drawing when fired from the same test barrel, delivered an average of 76.4% of their pellets into a 26%. inch circle at a range of 35 yards.

Example 3 12 gauge shotshells were hand-loaded in a conventional manner wherein a /8 inch thick cardboard, overpowder wad followed by 1% inch thick felt wad were employed. 1 /2 ounces of shot were placed directly in the body of the shell and the tube end was cr-imped closed. A sample of 10 shells thus loaded were fired from a test gun barrel and an average of 62.5 of the shot pellets were delivered into a 26% inch circle at 35 yards range. A second 10 rounds sample containing a similar 1 /2 ounce shot load but loaded as shown in FIGURE 6 of the drawing, employing the connected discs and the shot containing sleeve, delivered an average of 83.5% of its pellet load into a similar 26% inch circle at 35 yards range fired from the same test gun barrel.

The shotshell gas-sealing component and the shot-containing component may be made from any suitable thermoplastic material. Polyethylene of a density of about .92 has been found very suitable but it will be apparent to one skilled in the art that other kinds of materials may be successfiully employed. It should be appreciated, however, that a material subject to destruction under the conditions encountered during the initiation of a shotshell powder charge or in the passage of the components and shot load through the gun barrel would not be preferred. Furthenmore, a material which lends itself to fabrication into the desired shape, such as by moulding or casting by modern methods, is to be preferred in the interest of economy.

It will be obvious to one skilled in the ammunition art that the principle employed in the present invention to provide an eifective seal against the escape of propelling gases need not be limited to a shotshell wherein the shot is contained within a shot-enclosing component. The shot, for example, may be loosely loaded into the shotshell tube. A wedge-shaped wad of thermoplastic material may be located below any loose shot change and below such a wad, the cup-shaped gas-sealing component as shown in FIGURE 2 of the drawing, may be placed. In such a shotshell, the initiation of the powder charge will drive forward the cup-shaped component, the wedge-shaped wad thereby fitting into the cup and expanding the sides thereof to form a tight gas seal against the shotshell tube and barrel of the firearm. Similarly, it will be obvious to one skilled in the art that where a slug-loaded shotshell is employed, the base of the slug projectile may have located below thereof, a tapered section, which tapered section will tunction in the same manner as the tapered base section of the shot-enclosing component described heretofore.

What we claim is:

1. A shotshell comprising in combination a cup shaped metallic head having a central aperture, a primer cap mounted in said aperture, a tubular casing securely held by the side wall of said metallic head and extending beyond said wall and, within said tubular casing, a powder charge adjacent said primer cap, an outward faeing cupshaped resilient thermoplastic wad adjacent said powder charge and telescopically received within said casing, an outward-facing cup-shaped resilient thermoplastic shot container adjacent said wad and also telescopically received within said casing pelletized shot within said container and an end closure contiguous with said shot, the base portion of said shot container being adapted to progressively engage with the cup portion of said wad upon initiation of said powder charge, thereby causing lateral expansion of said wad and thus forming a gas-tight seal against the inner wall of said casing.

2. A shotshell as claimed in claim 1 wherein the cupshaped wad is internally tapered and the cup-shaped shot container has an inwardly tapered thick base and a thin side wall provided with at least two longitudinal slits extending from the top of said wall to approximately said thick base.

3. A shotshell as claimed in claim 1 wherein the Wad and shot container are made of polyethylene.

4. A shotshell comprising in combination a cup-shaped metallic head having a central aperture, a primer cap mounted in said aperture, a tubular casing securely held by the side wall of said metallic head and extending beyond said wall and within said tubular casing, a powder charge adjacent said primer cap, a resilient thenmoplastic wad adjacent said powder change and telescopically received within said casing and consisting of three thick circular discs securely held together at their cen ter in eqruispaced relationship, the lower and upper discs being peripherally tapered outwardly toward the intermediate disc, a resilient thermoplastic cylindrical shot container adjacent said wad and telescopically received within said casing and having an internal shoulder in its lower portion, pelletized shot within said container and an end closure contiguous with said shot, the upper portion of said wad being adapted to pressively engage with the lower portion of said shot container upon initiation of said powder charge, thereby causing lateral expansion of said container and thus forming a gas-tight seal against the inner wall of said casing.

5. A shotshell as claimed in claim 4 wherein the wall of the shot container is provided with at least two longitudinal slits extending from the top of said wall to approximately the internal shoulder.

6. A shotshell as claimed in claim 4 wherein the wad and shot container are made of polyethylene.

References Cited by the Examiner UNITED STATES PATENTS 3,022,731 2/ 1962 Yeoman 102--95 X 3,053,185 9/1962 Oberfell et al. 102-95 3,147,709 9/ 1964 Werner 10242 3,217,648 11/1965 Foote et al. 102-42 FOREIGN PATENTS 831,909 6/ 1938 France.

1,186,659 2/ 1959 France.

BENJAMIN A. BORCHELT, Primary Examiner.

ROBERT F. STAHL, Examiner. 

1. A SHOTSHELL COMPRISING IN COMBINATION A CUP-SHAPED METALLIC HEAD HAVING A CENTRAL APERTURE, A PRIMER CAP MOUNTED IN SAID APERTURE, A TUBULAR CASING SECURELY HELD BY THE SIDE WALL OF SAID METALLIC HEAD AND EXTENDING BEYOND SAID WALL AND, WITHIN SAID TUBULAR CASING, A POWDER CHARGE ADJACENT SAID PRIMER CAP, AN OUTWARD-FACING CUPSHAPED RESILIENT THERMOPLASTIC WAD ADJACENT SAID POWDER CHARGE AND TELESCOPICALLY RECEIVED WITHIN SAID CASING, AN OUTWARD-FACING CUP-SHAPED RESILIENT THERMOPLASTIC SHOT CONTAINER ADJACENT SAID WAD AND ALSO TELESCOPICALLY RECEIVED WITHIN SAID CASING PELLETIZED SHOT WITHIN SAID CONTAINER AND AN END CLOSURE CONTIGUOUS WITH SAID SHOT, THE BASE PORTION OF SAID SHOT CONTAINER BEING ADAPTED TO PROGRESSIVELY ENGAGE WITH THE CUP PORTION OF SAID WAD UPON INITIATION OF SAID POWDER CHARGE, THEREBY CAUSING LATERAL EXPANSION OF SAID WAD AND THUS FORMING A GAS-TIGHT SEAL AGAINST THE INNER WALL OF SAID CASING. 